1 use crate::consts::{constant, miri_to_const, Constant};
2 use crate::utils::paths;
3 use crate::utils::sugg::Sugg;
5 expr_block, is_allowed, is_expn_of, match_qpath, match_type, multispan_sugg, remove_blocks, snippet,
6 snippet_with_applicability, span_help_and_lint, span_lint_and_sugg, span_lint_and_then, span_note_and_lint,
9 use if_chain::if_chain;
10 use rustc::declare_lint_pass;
11 use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintContext, LintPass};
12 use rustc::ty::{self, Ty};
13 use rustc_errors::Applicability;
14 use rustc_hir::def::CtorKind;
16 use rustc_session::declare_tool_lint;
17 use rustc_span::source_map::Span;
18 use std::cmp::Ordering;
19 use std::collections::Bound;
20 use syntax::ast::LitKind;
22 declare_clippy_lint! {
23 /// **What it does:** Checks for matches with a single arm where an `if let`
24 /// will usually suffice.
26 /// **Why is this bad?** Just readability – `if let` nests less than a `match`.
28 /// **Known problems:** None.
32 /// # fn bar(stool: &str) {}
33 /// # let x = Some("abc");
35 /// Some(ref foo) => bar(foo),
41 "a `match` statement with a single nontrivial arm (i.e., where the other arm is `_ => {}`) instead of `if let`"
44 declare_clippy_lint! {
45 /// **What it does:** Checks for matches with two arms where an `if let else` will
48 /// **Why is this bad?** Just readability – `if let` nests less than a `match`.
50 /// **Known problems:** Personal style preferences may differ.
57 /// # fn bar(foo: &usize) {}
58 /// # let other_ref: usize = 1;
59 /// # let x: Option<&usize> = Some(&1);
61 /// Some(ref foo) => bar(foo),
62 /// _ => bar(&other_ref),
66 /// Using `if let` with `else`:
69 /// # fn bar(foo: &usize) {}
70 /// # let other_ref: usize = 1;
71 /// # let x: Option<&usize> = Some(&1);
72 /// if let Some(ref foo) = x {
78 pub SINGLE_MATCH_ELSE,
80 "a `match` statement with two arms where the second arm's pattern is a placeholder instead of a specific match pattern"
83 declare_clippy_lint! {
84 /// **What it does:** Checks for matches where all arms match a reference,
85 /// suggesting to remove the reference and deref the matched expression
86 /// instead. It also checks for `if let &foo = bar` blocks.
88 /// **Why is this bad?** It just makes the code less readable. That reference
89 /// destructuring adds nothing to the code.
91 /// **Known problems:** None.
96 /// &A(ref y) => foo(y),
103 "a `match` or `if let` with all arms prefixed with `&` instead of deref-ing the match expression"
106 declare_clippy_lint! {
107 /// **What it does:** Checks for matches where match expression is a `bool`. It
108 /// suggests to replace the expression with an `if...else` block.
110 /// **Why is this bad?** It makes the code less readable.
112 /// **Known problems:** None.
118 /// let condition: bool = true;
119 /// match condition {
124 /// Use if/else instead:
128 /// let condition: bool = true;
137 "a `match` on a boolean expression instead of an `if..else` block"
140 declare_clippy_lint! {
141 /// **What it does:** Checks for overlapping match arms.
143 /// **Why is this bad?** It is likely to be an error and if not, makes the code
146 /// **Known problems:** None.
152 /// 1...10 => println!("1 ... 10"),
153 /// 5...15 => println!("5 ... 15"),
157 pub MATCH_OVERLAPPING_ARM,
159 "a `match` with overlapping arms"
162 declare_clippy_lint! {
163 /// **What it does:** Checks for arm which matches all errors with `Err(_)`
164 /// and take drastic actions like `panic!`.
166 /// **Why is this bad?** It is generally a bad practice, just like
167 /// catching all exceptions in java with `catch(Exception)`
169 /// **Known problems:** None.
173 /// let x: Result<i32, &str> = Ok(3);
175 /// Ok(_) => println!("ok"),
176 /// Err(_) => panic!("err"),
179 pub MATCH_WILD_ERR_ARM,
181 "a `match` with `Err(_)` arm and take drastic actions"
184 declare_clippy_lint! {
185 /// **What it does:** Checks for match which is used to add a reference to an
188 /// **Why is this bad?** Using `as_ref()` or `as_mut()` instead is shorter.
190 /// **Known problems:** None.
194 /// let x: Option<()> = None;
195 /// let r: Option<&()> = match x {
197 /// Some(ref v) => Some(v),
202 "a `match` on an Option value instead of using `as_ref()` or `as_mut`"
205 declare_clippy_lint! {
206 /// **What it does:** Checks for wildcard enum matches using `_`.
208 /// **Why is this bad?** New enum variants added by library updates can be missed.
210 /// **Known problems:** Suggested replacements may be incorrect if guards exhaustively cover some
211 /// variants, and also may not use correct path to enum if it's not present in the current scope.
215 /// # enum Foo { A(usize), B(usize) }
216 /// # let x = Foo::B(1);
222 pub WILDCARD_ENUM_MATCH_ARM,
224 "a wildcard enum match arm using `_`"
227 declare_clippy_lint! {
228 /// **What it does:** Checks for wildcard pattern used with others patterns in same match arm.
230 /// **Why is this bad?** Wildcard pattern already covers any other pattern as it will match anyway.
231 /// It makes the code less readable, especially to spot wildcard pattern use in match arm.
233 /// **Known problems:** None.
242 pub WILDCARD_IN_OR_PATTERNS,
244 "a wildcard pattern used with others patterns in same match arm"
247 declare_lint_pass!(Matches => [
252 MATCH_OVERLAPPING_ARM,
255 WILDCARD_ENUM_MATCH_ARM,
256 WILDCARD_IN_OR_PATTERNS
259 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Matches {
260 fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
261 if in_external_macro(cx.sess(), expr.span) {
264 if let ExprKind::Match(ref ex, ref arms, MatchSource::Normal) = expr.kind {
265 check_single_match(cx, ex, arms, expr);
266 check_match_bool(cx, ex, arms, expr);
267 check_overlapping_arms(cx, ex, arms);
268 check_wild_err_arm(cx, ex, arms);
269 check_wild_enum_match(cx, ex, arms);
270 check_match_as_ref(cx, ex, arms, expr);
271 check_wild_in_or_pats(cx, arms);
273 if let ExprKind::Match(ref ex, ref arms, _) = expr.kind {
274 check_match_ref_pats(cx, ex, arms, expr);
280 fn check_single_match(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
281 if arms.len() == 2 && arms[0].guard.is_none() && arms[1].guard.is_none() {
282 if let PatKind::Or(..) = arms[0].pat.kind {
283 // don't lint for or patterns for now, this makes
284 // the lint noisy in unnecessary situations
287 let els = remove_blocks(&arms[1].body);
288 let els = if is_unit_expr(els) {
290 } else if let ExprKind::Block(_, _) = els.kind {
291 // matches with blocks that contain statements are prettier as `if let + else`
294 // allow match arms with just expressions
297 let ty = cx.tables.expr_ty(ex);
298 if ty.kind != ty::Bool || is_allowed(cx, MATCH_BOOL, ex.hir_id) {
299 check_single_match_single_pattern(cx, ex, arms, expr, els);
300 check_single_match_opt_like(cx, ex, arms, expr, ty, els);
305 fn check_single_match_single_pattern(
306 cx: &LateContext<'_, '_>,
310 els: Option<&Expr<'_>>,
312 if is_wild(&arms[1].pat) {
313 report_single_match_single_pattern(cx, ex, arms, expr, els);
317 fn report_single_match_single_pattern(
318 cx: &LateContext<'_, '_>,
322 els: Option<&Expr<'_>>,
324 let lint = if els.is_some() { SINGLE_MATCH_ELSE } else { SINGLE_MATCH };
325 let els_str = els.map_or(String::new(), |els| {
326 format!(" else {}", expr_block(cx, els, None, ".."))
332 "you seem to be trying to use match for destructuring a single pattern. Consider using `if \
336 "if let {} = {} {}{}",
337 snippet(cx, arms[0].pat.span, ".."),
338 snippet(cx, ex.span, ".."),
339 expr_block(cx, &arms[0].body, None, ".."),
342 Applicability::HasPlaceholders,
346 fn check_single_match_opt_like(
347 cx: &LateContext<'_, '_>,
352 els: Option<&Expr<'_>>,
354 // list of candidate `Enum`s we know will never get any more members
356 (&paths::COW, "Borrowed"),
357 (&paths::COW, "Cow::Borrowed"),
358 (&paths::COW, "Cow::Owned"),
359 (&paths::COW, "Owned"),
360 (&paths::OPTION, "None"),
361 (&paths::RESULT, "Err"),
362 (&paths::RESULT, "Ok"),
365 let path = match arms[1].pat.kind {
366 PatKind::TupleStruct(ref path, ref inner, _) => {
367 // Contains any non wildcard patterns (e.g., `Err(err)`)?
368 if !inner.iter().all(is_wild) {
371 print::to_string(print::NO_ANN, |s| s.print_qpath(path, false))
373 PatKind::Binding(BindingAnnotation::Unannotated, .., ident, None) => ident.to_string(),
374 PatKind::Path(ref path) => print::to_string(print::NO_ANN, |s| s.print_qpath(path, false)),
378 for &(ty_path, pat_path) in candidates {
379 if path == *pat_path && match_type(cx, ty, ty_path) {
380 report_single_match_single_pattern(cx, ex, arms, expr, els);
385 fn check_match_bool(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
386 // Type of expression is `bool`.
387 if cx.tables.expr_ty(ex).kind == ty::Bool {
392 "you seem to be trying to match on a boolean expression",
396 let exprs = if let PatKind::Lit(ref arm_bool) = arms[0].pat.kind {
397 if let ExprKind::Lit(ref lit) = arm_bool.kind {
399 LitKind::Bool(true) => Some((&*arms[0].body, &*arms[1].body)),
400 LitKind::Bool(false) => Some((&*arms[1].body, &*arms[0].body)),
410 if let Some((true_expr, false_expr)) = exprs {
411 let sugg = match (is_unit_expr(true_expr), is_unit_expr(false_expr)) {
412 (false, false) => Some(format!(
414 snippet(cx, ex.span, "b"),
415 expr_block(cx, true_expr, None, ".."),
416 expr_block(cx, false_expr, None, "..")
418 (false, true) => Some(format!(
420 snippet(cx, ex.span, "b"),
421 expr_block(cx, true_expr, None, "..")
424 let test = Sugg::hir(cx, ex, "..");
425 Some(format!("if {} {}", !test, expr_block(cx, false_expr, None, "..")))
427 (true, true) => None,
430 if let Some(sugg) = sugg {
433 "consider using an `if`/`else` expression",
435 Applicability::HasPlaceholders,
445 fn check_overlapping_arms<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ex: &'tcx Expr<'_>, arms: &'tcx [Arm<'_>]) {
446 if arms.len() >= 2 && cx.tables.expr_ty(ex).is_integral() {
447 let ranges = all_ranges(cx, arms, cx.tables.expr_ty(ex));
448 let type_ranges = type_ranges(&ranges);
449 if !type_ranges.is_empty() {
450 if let Some((start, end)) = overlapping(&type_ranges) {
453 MATCH_OVERLAPPING_ARM,
455 "some ranges overlap",
457 "overlaps with this",
464 fn is_wild<'tcx>(pat: &impl std::ops::Deref<Target = Pat<'tcx>>) -> bool {
466 PatKind::Wild => true,
471 fn check_wild_err_arm(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_>]) {
472 let ex_ty = walk_ptrs_ty(cx.tables.expr_ty(ex));
473 if match_type(cx, ex_ty, &paths::RESULT) {
475 if let PatKind::TupleStruct(ref path, ref inner, _) = arm.pat.kind {
476 let path_str = print::to_string(print::NO_ANN, |s| s.print_qpath(path, false));
478 if path_str == "Err";
479 if inner.iter().any(is_wild);
480 if let ExprKind::Block(ref block, _) = arm.body.kind;
481 if is_panic_block(block);
483 // `Err(_)` arm with `panic!` found
484 span_note_and_lint(cx,
487 "`Err(_)` will match all errors, maybe not a good idea",
489 "to remove this warning, match each error separately \
490 or use `unreachable!` macro");
498 fn check_wild_enum_match(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_>]) {
499 let ty = cx.tables.expr_ty(ex);
501 // If there isn't a nice closed set of possible values that can be conveniently enumerated,
502 // don't complain about not enumerating the mall.
506 // First pass - check for violation, but don't do much book-keeping because this is hopefully
507 // the uncommon case, and the book-keeping is slightly expensive.
508 let mut wildcard_span = None;
509 let mut wildcard_ident = None;
511 if let PatKind::Wild = arm.pat.kind {
512 wildcard_span = Some(arm.pat.span);
513 } else if let PatKind::Binding(_, _, ident, None) = arm.pat.kind {
514 wildcard_span = Some(arm.pat.span);
515 wildcard_ident = Some(ident);
519 if let Some(wildcard_span) = wildcard_span {
520 // Accumulate the variants which should be put in place of the wildcard because they're not
523 let mut missing_variants = vec![];
524 if let ty::Adt(def, _) = ty.kind {
525 for variant in &def.variants {
526 missing_variants.push(variant);
531 if arm.guard.is_some() {
532 // Guards mean that this case probably isn't exhaustively covered. Technically
533 // this is incorrect, as we should really check whether each variant is exhaustively
534 // covered by the set of guards that cover it, but that's really hard to do.
537 if let PatKind::Path(ref path) = arm.pat.kind {
538 if let QPath::Resolved(_, p) = path {
539 missing_variants.retain(|e| e.ctor_def_id != Some(p.res.def_id()));
541 } else if let PatKind::TupleStruct(ref path, ..) = arm.pat.kind {
542 if let QPath::Resolved(_, p) = path {
543 missing_variants.retain(|e| e.ctor_def_id != Some(p.res.def_id()));
548 let mut suggestion: Vec<String> = missing_variants
551 let suffix = match v.ctor_kind {
552 CtorKind::Fn => "(..)",
553 CtorKind::Const | CtorKind::Fictive => "",
555 let ident_str = if let Some(ident) = wildcard_ident {
556 format!("{} @ ", ident.name)
560 // This path assumes that the enum type is imported into scope.
561 format!("{}{}{}", ident_str, cx.tcx.def_path_str(v.def_id), suffix)
565 if suggestion.is_empty() {
569 let mut message = "wildcard match will miss any future added variants";
571 if let ty::Adt(def, _) = ty.kind {
572 if def.is_variant_list_non_exhaustive() {
573 message = "match on non-exhaustive enum doesn't explicitly match all known variants";
574 suggestion.push(String::from("_"));
580 WILDCARD_ENUM_MATCH_ARM,
584 suggestion.join(" | "),
585 Applicability::MachineApplicable,
590 // If the block contains only a `panic!` macro (as expression or statement)
591 fn is_panic_block(block: &Block<'_>) -> bool {
592 match (&block.expr, block.stmts.len(), block.stmts.first()) {
593 (&Some(ref exp), 0, _) => {
594 is_expn_of(exp.span, "panic").is_some() && is_expn_of(exp.span, "unreachable").is_none()
596 (&None, 1, Some(stmt)) => {
597 is_expn_of(stmt.span, "panic").is_some() && is_expn_of(stmt.span, "unreachable").is_none()
603 fn check_match_ref_pats(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
604 if has_only_ref_pats(arms) {
605 let mut suggs = Vec::new();
606 let (title, msg) = if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, ref inner) = ex.kind {
607 let span = ex.span.source_callsite();
608 suggs.push((span, Sugg::hir_with_macro_callsite(cx, inner, "..").to_string()));
610 "you don't need to add `&` to both the expression and the patterns",
614 let span = ex.span.source_callsite();
615 suggs.push((span, Sugg::hir_with_macro_callsite(cx, ex, "..").deref().to_string()));
617 "you don't need to add `&` to all patterns",
618 "instead of prefixing all patterns with `&`, you can dereference the expression",
622 suggs.extend(arms.iter().filter_map(|a| {
623 if let PatKind::Ref(ref refp, _) = a.pat.kind {
624 Some((a.pat.span, snippet(cx, refp.span, "..").to_string()))
630 span_lint_and_then(cx, MATCH_REF_PATS, expr.span, title, |db| {
631 if !expr.span.from_expansion() {
632 multispan_sugg(db, msg.to_owned(), suggs);
638 fn check_match_as_ref(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
639 if arms.len() == 2 && arms[0].guard.is_none() && arms[1].guard.is_none() {
640 let arm_ref: Option<BindingAnnotation> = if is_none_arm(&arms[0]) {
641 is_ref_some_arm(&arms[1])
642 } else if is_none_arm(&arms[1]) {
643 is_ref_some_arm(&arms[0])
647 if let Some(rb) = arm_ref {
648 let suggestion = if rb == BindingAnnotation::Ref {
654 let output_ty = cx.tables.expr_ty(expr);
655 let input_ty = cx.tables.expr_ty(ex);
657 let cast = if_chain! {
658 if let ty::Adt(_, substs) = input_ty.kind;
659 let input_ty = substs.type_at(0);
660 if let ty::Adt(_, substs) = output_ty.kind;
661 let output_ty = substs.type_at(0);
662 if let ty::Ref(_, output_ty, _) = output_ty.kind;
663 if input_ty != output_ty;
671 let mut applicability = Applicability::MachineApplicable;
676 &format!("use `{}()` instead", suggestion),
680 snippet_with_applicability(cx, ex.span, "_", &mut applicability),
690 fn check_wild_in_or_pats(cx: &LateContext<'_, '_>, arms: &[Arm<'_>]) {
692 if let PatKind::Or(ref fields) = arm.pat.kind {
693 // look for multiple fields in this arm that contains at least one Wild pattern
694 if fields.len() > 1 && fields.iter().any(is_wild) {
697 WILDCARD_IN_OR_PATTERNS,
699 "wildcard pattern covers any other pattern as it will match anyway.",
700 "Consider handling `_` separately.",
707 /// Gets all arms that are unbounded `PatRange`s.
708 fn all_ranges<'a, 'tcx>(
709 cx: &LateContext<'a, 'tcx>,
710 arms: &'tcx [Arm<'_>],
712 ) -> Vec<SpannedRange<Constant>> {
716 ref pat, guard: None, ..
719 if let PatKind::Range(ref lhs, ref rhs, range_end) = pat.kind {
721 (Some(lhs), Some(rhs)) => {
722 let lhs = constant(cx, cx.tables, lhs)?.0;
723 let rhs = constant(cx, cx.tables, rhs)?.0;
724 let rhs = match range_end {
725 RangeEnd::Included => Bound::Included(rhs),
726 RangeEnd::Excluded => Bound::Excluded(rhs),
728 return Some(SpannedRange {
733 (None, Some(rhs)) => {
734 let lhs = miri_to_const(ty.numeric_min_val(cx.tcx)?)?;
735 let rhs = constant(cx, cx.tables, rhs)?.0;
736 let rhs = match range_end {
737 RangeEnd::Included => Bound::Included(rhs),
738 RangeEnd::Excluded => Bound::Excluded(rhs),
740 return Some(SpannedRange {
745 (Some(lhs), None) => {
746 let lhs = constant(cx, cx.tables, lhs)?.0;
747 let rhs = miri_to_const(ty.numeric_max_val(cx.tcx)?)?;
748 return Some(SpannedRange {
750 node: (lhs, Bound::Excluded(rhs)),
757 if let PatKind::Lit(ref value) = pat.kind {
758 let value = constant(cx, cx.tables, value)?.0;
759 return Some(SpannedRange {
761 node: (value.clone(), Bound::Included(value)),
770 #[derive(Debug, Eq, PartialEq)]
771 pub struct SpannedRange<T> {
773 pub node: (T, Bound<T>),
776 type TypedRanges = Vec<SpannedRange<u128>>;
778 /// Gets all `Int` ranges or all `Uint` ranges. Mixed types are an error anyway
779 /// and other types than
780 /// `Uint` and `Int` probably don't make sense.
781 fn type_ranges(ranges: &[SpannedRange<Constant>]) -> TypedRanges {
784 .filter_map(|range| match range.node {
785 (Constant::Int(start), Bound::Included(Constant::Int(end))) => Some(SpannedRange {
787 node: (start, Bound::Included(end)),
789 (Constant::Int(start), Bound::Excluded(Constant::Int(end))) => Some(SpannedRange {
791 node: (start, Bound::Excluded(end)),
793 (Constant::Int(start), Bound::Unbounded) => Some(SpannedRange {
795 node: (start, Bound::Unbounded),
802 fn is_unit_expr(expr: &Expr<'_>) -> bool {
804 ExprKind::Tup(ref v) if v.is_empty() => true,
805 ExprKind::Block(ref b, _) if b.stmts.is_empty() && b.expr.is_none() => true,
810 // Checks if arm has the form `None => None`
811 fn is_none_arm(arm: &Arm<'_>) -> bool {
813 PatKind::Path(ref path) if match_qpath(path, &paths::OPTION_NONE) => true,
818 // Checks if arm has the form `Some(ref v) => Some(v)` (checks for `ref` and `ref mut`)
819 fn is_ref_some_arm(arm: &Arm<'_>) -> Option<BindingAnnotation> {
821 if let PatKind::TupleStruct(ref path, ref pats, _) = arm.pat.kind;
822 if pats.len() == 1 && match_qpath(path, &paths::OPTION_SOME);
823 if let PatKind::Binding(rb, .., ident, _) = pats[0].kind;
824 if rb == BindingAnnotation::Ref || rb == BindingAnnotation::RefMut;
825 if let ExprKind::Call(ref e, ref args) = remove_blocks(&arm.body).kind;
826 if let ExprKind::Path(ref some_path) = e.kind;
827 if match_qpath(some_path, &paths::OPTION_SOME) && args.len() == 1;
828 if let ExprKind::Path(ref qpath) = args[0].kind;
829 if let &QPath::Resolved(_, ref path2) = qpath;
830 if path2.segments.len() == 1 && ident.name == path2.segments[0].ident.name;
838 fn has_only_ref_pats(arms: &[Arm<'_>]) -> bool {
843 PatKind::Ref(..) => Some(true), // &-patterns
844 PatKind::Wild => Some(false), // an "anything" wildcard is also fine
845 _ => None, // any other pattern is not fine
848 .collect::<Option<Vec<bool>>>();
849 // look for Some(v) where there's at least one true element
850 mapped.map_or(false, |v| v.iter().any(|el| *el))
853 pub fn overlapping<T>(ranges: &[SpannedRange<T>]) -> Option<(&SpannedRange<T>, &SpannedRange<T>)>
857 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
859 Start(T, &'a SpannedRange<T>),
860 End(Bound<T>, &'a SpannedRange<T>),
863 impl<'a, T: Copy> Kind<'a, T> {
864 fn range(&self) -> &'a SpannedRange<T> {
866 Kind::Start(_, r) | Kind::End(_, r) => r,
870 fn value(self) -> Bound<T> {
872 Kind::Start(t, _) => Bound::Included(t),
873 Kind::End(t, _) => t,
878 impl<'a, T: Copy + Ord> PartialOrd for Kind<'a, T> {
879 fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
880 Some(self.cmp(other))
884 impl<'a, T: Copy + Ord> Ord for Kind<'a, T> {
885 fn cmp(&self, other: &Self) -> Ordering {
886 match (self.value(), other.value()) {
887 (Bound::Included(a), Bound::Included(b)) | (Bound::Excluded(a), Bound::Excluded(b)) => a.cmp(&b),
888 // Range patterns cannot be unbounded (yet)
889 (Bound::Unbounded, _) | (_, Bound::Unbounded) => unimplemented!(),
890 (Bound::Included(a), Bound::Excluded(b)) => match a.cmp(&b) {
891 Ordering::Equal => Ordering::Greater,
894 (Bound::Excluded(a), Bound::Included(b)) => match a.cmp(&b) {
895 Ordering::Equal => Ordering::Less,
902 let mut values = Vec::with_capacity(2 * ranges.len());
905 values.push(Kind::Start(r.node.0, r));
906 values.push(Kind::End(r.node.1, r));
911 for (a, b) in values.iter().zip(values.iter().skip(1)) {
913 (&Kind::Start(_, ra), &Kind::End(_, rb)) => {
914 if ra.node != rb.node {
915 return Some((ra, rb));
918 (&Kind::End(a, _), &Kind::Start(b, _)) if a != Bound::Included(b) => (),
919 _ => return Some((a.range(), b.range())),